Lifted System.IO.Temp

[heitor-lassarote]

I've noticed that unliftio's UnliftIO.Temporary doesn't lift temporary's System.IO.Temp, but instead reimplements most of that module.

As far as I understand, the main difference between both is that temporary will create the file/temporary template based on a random string, while unliftio will use the process's PID. This may actually have surprising behavior with concurrent programs (e.g., see this issue: UnkindPartition/temporary#8), where race conditions can happen. temporary mitigates this problem.

Is there any reason unliftio reimplements the module? Wouldn't it make it easier to keep up with updates in that library?

One more thing: why not re-export getCanonicalTemporaryDirectory?